Li_4Ti_5O_(12) prepared by a modified citric acid sol-gel method for lithium-ion battery

摘要

Li_4Ti_5O_(12) was synthesized by a modified and facile sol-gel method with ethylene diamine tetraacetic acid (EDTA) and citric acid (CA) as a bi-components chelating agent. The raw precursor and powders further calcined at various temperatures and holding time were characterized by XRD, FT-IR, TG, BET and SEM. Nano-scale Li_4Ti_5O_(12)oxides, with a high phase purity and good stoichiometry, can be obtained at a calcination temperature of 750 ℃ and higher. The Li_4Ti_5O_(12) nanoparticle shows a network morphology with high dispersion, which reached a capacity of 164 and 108 mAh g~(-1) at 1C and 10C discharge rate, respectively. The result of the cycling performance shows a high capacity maintenance ratio of 97% at 1C and 25 ℃ after 1000 cycles. Electrochemical lithium intercalation/extraction performance is also evaluated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) at room temperature.